At a high school in Washington, D.C., this past week, Bridget Cronin looked on as public school workers shuffled through the two dozen vaccination stations that lined the building's atrium.
Volunteers alternated waving green placards to usher in the next patient. Red placards were on hand to signal the need for more vaccine doses.
The mass vaccination event to immunize teachers and other public school workers in the district, held at Dunbar High School, was the culmination of weeks of long planning.
"We've got a cool flow going, where people can quickly come, get assessed by a doctor or nurse, pharmacist at the table," said Cronin, vice president of operations integration at nearby Children's National Hospital, who was in charge of setting up and overseeing the vaccine drive. "It's all one-way traffic all the way through the site to keep everything moving."
By the day's end, more than 1,750 D.C. Public Schools employees got their second shot of the Pfizer-BioNTech vaccine, out of about 7,600 DCPS workers in all.
The event relied on the support of Children's National medical staff — who volunteered their unpaid time to help with the effort. Many of the volunteers and those in line to receive the vaccine see the effort as a promising route to get teachers and kids back in the classroom. Since the pandemic forced schools to close nearly a year ago, mental health professionals have noted a spike in levels of anxiety and depression in children.
And re-opening schools is critical for the working parents reliant on child care who are needed to revive the economy.
In a CNN town hall last week, President Biden said teachers and other school workers should be "on the list of preferred" to get a COVID-19 vaccine.
Yet the vaccination campaign at Dunbar High offers just a glimpse of some of the enormous challenges ahead to pull off the biggest vaccination campaign in U.S. history, geared toward lifting the country out of the coronavirus pandemic.
Accountability at every step
At Dunbar, volunteer staff set up a pop-up laboratory in a repurposed science laboratory where the reserve Pfizer vaccines had been stored in a loaned-out fridge. But even before the vaccines reached volunteer hands, a fragile process was at work to transport the precious commodity.
The morning of the vaccine drive, hospital staff retrieved the vials from ultra-cold storage at Children's National for dethawing.
Due to fears of vaccine theft, the vaccine supply was then moved to the high school under the vigilant watch of security personnel.
"We're treating it the same thing as a narcotic because it is highly sought after," said Dr. Sean Tan, the director of pharmacy operations at Children's National. "We believe if we don't have all these safeguards in place we are vulnerable and we open ourselves to be targets."
Back at the high school, technicians prepared the vaccine-filled syringes in a time-consuming — and time-sensitive — procedure. Each vial had to be diluted and pulled into the syringe with certain steadiness.
Kellie Neal, a pharmacy technician supervisor at Children's National, had to go through special training to work with the Pfizer vaccine.
"We don't want to inject any air bubbles and we want to make sure they get the full dose," Neal said.
Dr. Tan said no drop can be spared.
"This is where technique and patience comes in," he said. "A lot of people are like, 'Oh, it's just a drop, I'll give up, I go to the next vial.' But we literally take every drop out of each vial," he said, because "just a drop might be a third of a dose."
The prepared syringes were then delivered to the doctors and nurses who administered the injections.
"We're in this together"
Cronin said a total of 125 volunteers from the hospital participated in the vaccine event. They held another round later in the week to vaccinate additional school workers.
"We created a gigantic sign-up sheet," she said. "The vaccine is free through the Department of Health, and then it's through the goodness of people's hearts that they're here today to get our city and everyone out of this pandemic."
But Washington's dependence on that generosity is also a symptom of a piecemeal, disjointed process in which Americans are getting vaccinated.
It took about a 2-hour wait for some of the school workers to make it to one of 24 tables where they were able to get the shot. Still, Cronin said mass vaccinations like this are more efficient than small-scale supermarket and pharmacy signups when it comes to inoculating large groups.
"We see 24 patients every 5 minutes," she said.
Back at the one of the stations, Dr. Craig DeWolfe, a pediatric hospitalist whose child attends a D.C. school, asked principal Amelia Hunt a series of medical questions before administering her second shot of the Pfizer vaccine.
"It means so much to me to be able to give back to these teachers and the principals and all the staff who have given so much to my son, our family. We're in this together for sure," DeWolfe told Hunt.
Hunt returned the gratitude.
"I appreciate you tremendously," she said. "I can't imagine what your job has been like and what the experience has been like being on the front lines of all this, so thank you for volunteering your time to come in and do this."
It will take many months to get teachers across the country vaccinated. And questions remain about the threats of new coronavirus variants and potential infection surges that could leave teachers exposed.
The D.C. Teachers' Union has said that opening schools safely requires more than vaccines. It has stipulated that community transmission must be low and that there needs to be measures in place, like good ventilation and cleaning protocols.
Another challenge: vaccine hesitancy
Logistics aside, there are also still many teachers who are reluctant to get vaccinated. According to DCPS, only 64% of teachers who were invited to be part of the vaccination clinic signed up. That number dropped to 45% when accounting for other support staff. And even after showing up at the site ready to be vaccinated, people have questions.
"I think the first and most important thing we can do as medical professionals when dealing and talking with people about their own potential hesitancy is acknowledge our own hesitancy," said Dr. Nathaniel Beers, a pediatrician at Children's National.
"Six months ago, I, too, was hesitant to think about potentially getting the vaccine," he said, "but taking the time to understand the science behind it, to understand that, while the vaccine itself is new, the technology that they use to develop the vaccine has been in development for many years. "
"A positive step forward"
But for principal Hunt, the vaccination drive felt like the start of a new chapter.
"I'm so excited because it means that we are taking that step forward, that positive step forward," she said.
The day she got her second coronavirus vaccine dose, she said, her school was marking a "Random Acts of Kindness Week."
"If there's something that I could do to be kind to someone else, it's getting this vaccine — because it means I'm keeping myself safe but I'm keeping my neighbors safe as well," she said.
Hiba Ahmad and Melissa Gray produced and edited the broadcast versions of this story.